GRAND CANYON NATIONAL PARK, Ariz. (AP) — Entrance gates to the Grand Canyon remained unlocked Monday with no one collecting fees during the federal government shutdown. Visitors were free to hike trails at the national park, stay in the campgrounds, and use river and backcountry permits they already had. Concessionaries are keeping lodges, campgrounds, restaurants and retail shops open. But anything run by the National Park Service, such as visitors centers and permit offices, was shut down.